1. Field of the Invention
The present invention relates to a probe card to contact with an object to be inspected to inspect electric properties of the object to be inspected.
2. Description of the Related Art
Inspection of electric properties of an electronic circuit such as an IC, LSI, or the like formed, for example, on a semiconductor wafer is performed by bringing, for example, a plurality of probe needles arranged on the lower surface of a probe card into electrical contact with electrode pads of the electronic circuit on the wafer. Therefore, the probe needles need to be arranged in alignment with the positions of the respective electrode pads.
However, the pattern of the electronic circuit has become finer in which the electrode pads have been made finer and intervals between the electrode pads have become smaller. This requires formation of fine contact portions at a narrow pitch, such as those with a width dimension of 100 μm or less and at a pitch of 180 μm or less. Hence, use of an anisotropic conductive sheet instead of the probe needles is proposed (Japanese Patent No. 3038859). The anisotropic conductive sheet is a sheet having a plurality of elastic conductive portions protruding from one surface of the sheet being an insulating portion, in which the conductive portions can be formed very fine at a narrow pitch.